浏览器中的XPath 3 [英] XPath 3 in browser

问题描述

当我们看到一致性图表时，例如 https://caniuse.com/#search=xpath和 https：// developer。 microsoft.com/en-us/microsoft-edge/platform/status/domlevel3xpath/?q=xpath ，通常与 DOM级别3 XPath ，其重点是使用XPath 1.0 来访问DOM对象，但不一定是XPath 3.0或

When we see conformance chart, such as https://caniuse.com/#search=xpath and https://developer.microsoft.com/en-us/microsoft-edge/platform/status/domlevel3xpath/?q=xpath, it's usually about DOM Level 3 XPath that focuses on accessing DOM object using XPath 1.0, but not necessarily XPath 3.0 or higher.

问题1-W3C等对浏览器是否有明确的版本要求，以支持较新版本的XPath？

Question 1 - Is there any explicit version requirement for browsers by W3C etc. to support newer versions of XPath?

此XPath 1.0功能有效：

This XPath 1.0 feature works:

document.evaluate(
  'normalize-space(" X  ")',
  document, null, XPathResult.ANY_TYPE, null ).stringValue

// => "X"

但这是XPath 3.0内联函数功能（ ref ）抛出：

But this XPath 3.0 inline-function feature (ref) throws:

document.evaluate(
  'let $incr := function($n as xs:integer) as xs:integer { $n +1 } return $incr(2)',
  document, null, XPathResult.ANY_TYPE, null ).stringValue

Edge：

XPATH15001：XPath查询 let $ incr：= function（$ n as xs：integer）as xs：integer {$ n +1} return $ incr（2）不支持

XPATH15001: XPath query "let $incr := function($n as xs:integer) as xs:integer { $n +1 } return $incr(2)" not supported

Firefox：

SyntaxError：该表达式不是合法表达式。

SyntaxError: The expression is not a legal expression.

问题2-如果假设存在错误，是否允许浏览器使用XPath 3.0在我的代码中；那么v3.1功能（例如箭头功能）如何？

Question 2 - If XPath 3.0 is allowed in browser, assuming bug in my code; then how about v3.1 features (such as arrow-functions), are those also allowed?

推荐答案

没有浏览器原生支持XPath 2.0 ，更不用说XPath 3.0。

No browsers support XPath 2.0 natively, let alone XPath 3.0.

请注意，与XSLT不同，XPath除了确定给定版本支持的功能并观察是否发生错误外，没有确定XPath实现版本的内在方法 ，就像您一样。

Note also that XPath, unlike XSLT, doesn't have an intrinsic way of determining the version of an XPath implementation other than trying a function supported by a given version and observing whether an error occurs, as you've done.

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